An economy or market with no regulation or restrictions on how the
said market operates, thus allowing the most efficient allocation of a resources in an economy. The laissez-faire or 'market
system' is the unplanned
capitalist economic system. The extreme opposite is N.Korea, Cuba, China etc.
The '
passive' approach, or that of non-intervention to Macroeconomic management (as stated by
harry flashman) is just one feature of the laissez-faire or market
system.